Metronome



April 27, 1937- I .1. H. MORRISON 2,678,505

METRONOME Filed Dec. 18, 1935v INVENTOR,

. struction.

Patented Apr. 27, 1937 UNITED STATES PATENT OFFICE 5 Claims.

My invention relates to timing devices and more particularly to an electrically actuated, metronome.

An object of my invention is to provide a metronome having a constant and continuous source of power so as to overcome the necessity of winding a spring motor as is the case in the majority of metronomes in present use.

Another object of my invention is to provide an electric motor driven metronome in which the mechanism for striking beats is electricaily actuated in order to reduce the power required of said motor.

A further object of my invention is to provide a metronome which is accurate and dependable in operation and yet extremely simple in con- Further objects and advantages will be made manifest in the following description taken in connection with the accompanying drawing in which:

Fig. .1 is a iront elevational view o a preferred form of metronome of my invention.

Fig. 2 is a side elevational View of the metronome shown in Fig. l with one side of the hous ing broken away to disclose the interior of the` device.

Fig. 3 is a vertical sectional View taken on the line 3-3 of Fig. 2.

Fig. 4 is an enlarged, fragmentary sectional View taken on the line 4-4 of Fig. 2.

Fig. 5 is a vertical sectional view taken on the line 5-5 of Fig. 4, and Y Fig. 6 is a wiring diagram of the metronome of my invention.

Referring speciically to the drawing, a metronome I comprising a preferred embodiment of my invention, includes a housing 2 having a front panel 3 and Va base plate 4. Mounted on the' panel 3 is a bearing 5, shown in Fig. 2, in which a shaft 6 is rotatably mounted. Fixed on the shaft 6 isa dial 'l and a pinion 8. Mounted on the panel 3 below the dial l are switches E, 9 and ID as shown in Fig. l. Switch 9 has four contact points a, b, c, and d, and switch Ill has two contact points e and f as shown diagrammatically in Fig. 6.

Extending upward from the base plate t are lugs I I in which a pin i2 is xed, the latter carrying the lower end of an oscillating4 arm Bil. Mounted onl the upper end of the arm i3 is a sector'gear I4 disposed in meshing relation with 'the aforementioned pinion 8. Pivotally mounted on the arm I3 by means of a screw ISa is a yoke I5 .in which a shaft I6 is journalled. The yoke i5 is urged rightward, as viewed in Fig. 2 by means of a spring lll on the screw i3d.

Fixed on the shaft l@ is a wheel lil and contact drums i9, "viii, 2t, 22 and 2'3, each of the .latter being formed to provide contact points 2li separated by segments 25 oi insulating material as shown in Fig. 5. -The drum i9 has 12 equally spaced contact points while the drums 2d, 2i, 22 and 23 have 2, 3, 4. and 6 equally spaced contact points respectively. Fixed on top of the yoke if is a bar 2l of insulating material in which brushes 2da, 23h, 28e, Litd and 23e are slidably mounted as seen in Fig. 4, there being wires Stia Sib, elle, Sila? and 3de extending from the respective brushes 28d to 528e.

Secured 'to the base plate fl is a housing 3l' to with a synchronous electric motor E@ is fixed by means oi lugs fill. Rotatably mounted on the housing is a disc D, there being suitable reduction gearing within the housing '3l for transmitting rotation ci the motor tothe disc D, the latter being driven at a relatively slow speed in the direction indicated by the arrow in Fig. 3. As shown in Fig. 2, the face of the disc D contacts the periphery of the wheel lil and the disc moves downward relative to the wheel so that the resistance of the wheel to rotation tends to rock the yoke i5 on the screw 03a toward disc D to increase the pressure of the wheel I8 against the disc D in proportion to the amount of power required to drive the wheel it.

Secured to the back wall of the housing 2 is a striker S comprising a bracket 43 upon which magnets il and i2 and a hammer M are mounted as shown in Fig. 2. Provided on the panel 3 above the dial 'l' is a light 35, and on the side of the housing 3 is a 3-way jack 36, the purpose of which will be described hereafter;

Referring now to Fig. 6, in'which I have shown a wiring diagram of the metronome l, a suitable source of electrical current such as a. battery B is shown having one lead grounded to the frame of the metronome as indicated at G. The remaining lead of the battery B is connected to the arm of the switch Ml. One of the contacts e of the switch lll is connected by a wire 50 to one of the receptacles of the jack 3d, while the other contact of the switch i@ is connected to one side of each of the magnets li and 42 by a wire 5l. The shaft it upon which the drums I 9 to 23 are mounted is grounded by a wire indicated at k52 thus enabling the contacts 24 of the drums to receive current from the grounded side of the battery B.

The wire 30a extends from the brush'28a of the drum I9 to one side of the magnet 4I and the wires 30h, 30C, 30d and 30e are connected to contacts a, b, c and d respectively of the switch 9, the arm of the switch 9 being connected by a wire 53 to one side of the magnet 42. Joined to the wire 53 and extending to another of the receptacles of the jack 36 is a Wire 54, the remaining receptacle of the jack 36 being connected to the wire 30a by a wire 55.

Suitable wires, not shown, supply electric current to the motor 39 which is controlled by the switch 8 shown in Fig. 1.

Operation When the switch 8 is turned on the motor 39 is energized causing the disc D to rotate counterclockwise as viewed in Fig. 3. The wheel I8 and drums I9, 20, 2|, 22 and 23 are rotated by thedisc D. The dial 1 is set so that thel number indicating the desired number of beats per minute is opposite the mark indicated at M in Fig. 1. The switch I is then turned so that the arm thereof rests on the contact f thus supplying current from one side of the battery B to one side of the magnet 4I, the circuit to the latter being completed each time one of the contacts` 24 of the drum I9 engages the brush 28a. The intermittent supply of current to the magnet 4I causes the hammer 44 to strike the required number of beats per minute on the housing 2. When desirable to accent every sixth beat of the hammer 44 the switch 9 is set so that the arm thereof engages the contact a and each time one of the contacts 24 of the drum 20 engages the brush 28h the circuit is completed to the magnet 42, the latter acting simultaneously with the magnet 4I to increase the velocity of the hammer 44 so as' to accent every sixth beat. In a like manner every fourth, third or second beat of the hammerl 44 may be accented by engagement of the arm of the switch 9 with the contact b, c or d respectively. The light 35 is connected across the wires 30a and I so as to flash each time the magnet 4I is energized to provide. visual signals in addition to the audible signals.

For the purpose of providing audible and visual signals at a point remote from the metronome I, an extension unit (not shown) is used in connection with the metronome of my invention.

The extension unit comprises a housing similar to the housing 2 of the metronome I, in which a striker and light are provided, the latter being identical with the striker S and light of the metronome I.

Extending from the extension unit is a three wire cord 6I! having a plug 6I on the end thereof as shown in Fig. 6. When the plug 6I is inserted into the jack 36 and the switch I0 positioned as shown in Fig. 6, the striker and light of the extension unit are energized in the same manner described relative to the metronome I.

Although I have shown and described but one preferred form of my invention it is understood that various modifications and changes might be made therein without departing from the spirit of the invention or the scope of the appended claims.

I claim as my invention:

1. In a metronome, the combination of: primary electrically operatedy means for striking audible signals; secondary electrically operated means for accenting certain of said signals; a primary power driven drum having a plurality of equally spaced contact points thereon and a brush riding on (said drum for engagement with said contact points, said drum and said brush supplying intermittent charges of current to said primary means to produce a series of audible signals; a secondary drum rotatable with said primary drum; Contact points on Said secondary drum and a brush riding on said secondary drum for engagement with said contact points simultaneously with the engagement of certain of said contacts and said brush of said primary drum, said secondary drum supplying intermittent charges of current to said secondary means so as to accent certain of said audible signals.

2. In a metronome, the combination of electrically operated means for striking audible signals; electrically operated means for accenting certain of said audible signals; a primary rotary switch having a plurality of contacts for intermittently energizing said signal means; a second rotary switch having one sixth as many contacts as said primary switch; a third rotary switch having one fourth as many contacts as said primary switch; a fourth rotary switch having one third as manycontacts as said primary switch; a ith rotary switch having one half as many contacts as said primary switch; power means for driving all of said switches at a common rate of speed; means for connecting any one of said second, third, fourth, or fifth switches to the circuit of said signal accenting means to accent every sixth, fourth, third or second of said audible signais.

3. A combination as in claim 2 in which control means is provided for changing the speed of said power means to cause said signal means to strike any desirable number of signals per minute.

4. In a metronome, the combination of: a hammer for striking audible signals; a magnet for actuating said hammer; means forA supplying charges of current at regular intervals to cause said hammer to strike equally timed signals; a second magnet adjacent said rst magnet; and means for supplying current to said second magnet simultaneously with certain of said charges supplied to said iirst magnet; said second magnet coacting with said rst magnet to increase the velocity of said hammer to produce an accented signal.

5. In combination as in claim 4 in which switch means is provided for energizing said second magnet on every second, third, fourth or sixth beat of said hammer.

JAMES H. MORRISON. 

